ANNOUNCER: He was a mobster the FBI could not catch. Deborah Feyerick takes you inside one of the biggest manhunts in FBI history.

(END OF VIDEO CLIP)

FEYERICK (voice-over): The church bells of St. Monica near the harbor in south Boston have sounded for generations of Irish immigrants. It's a tight-knit community that has always protected its own, a place James "Whitey" Bulger, one of Boston's most notorious gangsters, called home.

Bulger learned to fight and survive on the mean streets of south Boston, known as Southy to locals like John Shea who, decades later, would work for Bulger.

JOHN "RED" SHEA, FORMER BULGER ASSOCIATE: The guy was legendary. He made tough guys shake. He made them shake.

FEYERICK: Bulger's life of crime started early. Arrested in his teens, he was robbing banks by age 20. His shock of blonde hair earning him the name "Whitey," a name he is said to despite.

With his rugged good looks and reckless flamboyance, Bulger imagined himself Boston's version of Hollywood gangster Jimmy Kagny. But instead of red carpets he was headed to Alcatraz. A string of bank robberies landing Bulger 10 years in federal prison at age 25. He did his time and upon release vowed he would never, ever go back.

DICK LEHR, CO-AUTHOR, BLACK MASS: They had no hard proof.

FEYERICK: "Boston Globe" reporters Dick Lehr and Gerald O'Neill ultimately uncovered the deal he cut to make sure of that.

GERALD O'NEILL, CO-AUTHOR, BLACK MASS: He go out of prison in 1965 and we started doing research in 1988. And he hadn't gotten so much as a parking ticket.

FEYERICK: Whitey Bulger fresh from prison went to work as a mob enforcer. But Bulger warranted more and federal investigators say he'd stop at nothing to get it.

O'NEILL: Then he went on a killing rampage. I think it is like a month. He killed six guys in 1972.

LEHR: He was ambitious in making his move.

FEYERICK: And he was making his move with this man -- Steve Flemmy, aka, the rifle man. Among their alleged victims, Flemmy himself testified his own girlfriend, Deborah Davis.

FUENTES: Back in those days before DNA was in use to identify victims he would personally get involved in cutting off the fingers or hands of the victims and extracting their teeth.

FEYERICK (voice-over): But why kill Debbie Davis? Authorities say because she knew Bulger's secret connection with another kid from Southy, John Connelly.

LEHR: For him it was like meeting Ted Williams. And the idea of equating, you know --

FEYERICK (on camera): A gangster to a baseball player.

LEHR: A gangster to a baseball icon like that I think that shows you the kind of twisted values in perception on the world that is part of John Connelly.

FEYERICK (voice-over): John Connelly was a young, ambitious FBI agent who grew up in the same housing projects. Back in the '70 and '80s, the FBI's number one priority was taking down the Italian mafia. Bulger became Connelly's priced informant.

LEHR: And he did everything including breaking all kinds of laws over the years to keep that alive. FEYERICK: In a series of groundbreaking articles for the "Boston Globe" Lehr and O'Neill uncovered what their FBI sources call a dangerous alliance.

O'NEILL: In 1976 Connelly tipped him off about a rival (INAUDIBLE) and Bulger killed him. So Connelly had to realize right away how serious and deadly this arrangement was.

FEYERICK: Protected by Connelly and others, Bulger's criminal enterprise skyrocketed. Court documents show Bulger knew when police were watching, knew when they were moving in and ultimately knew when to disappear.

(On camera): He was shaking down bookmakers and loan sharks. This was a guy who was a really bad guy.

SHEA: Everything that I wanted to be.

FEYERICK (voice-over): As his power grew, so did that of his younger brother, Billy.

UNIDENTIFIED MALE: I just want you to know we're all on this open microphone, Mr. President.

FEYERICK: A tough as nails politician well respected as president of the Massachusetts State Senate.

SHEA: How do you beat a guy psychopathic with intelligence and the connection that he has in that world. Brother is a Senate. FBI is protecting him. It was, you know, one big family living in the projects like this.

FEYERICK: John Shea, now a changed man, once ran Bulger's multi- million dollar drug operation.

SHEA: Growing you up, hey, you know, you had to be a tough kid to handle.

FEYERICK: He served 12 years in prison rather than break Southy's code of silence.

SHEA: Whitey being a rat. Stevie being a rat. And this is what I took an oath to? An oath of honor? It was heartbreaking.

FEYERICK: Documents show FBI Agent Connelly continued to feed Bulger secret information, at times with deadly results.

WILLIAM CHRISTIE, ATTORNEY, BULGER VICTIMS: If Bulger got charged with a crime, then he could no longer be an informant.

FEYERICK: Attorney Bill Christie represents families of several of Bulger's alleged victims. Including the family of Bill Halloran, a drug dealer who cut a deal with the FBI. Only to be gunned down as he left a popular Boston restaurant.

According to testimony at a civil trial, FBI Agent Connelly told Bulger where to find Halloran.

CHRISTIE: Bulger cornered him and shot him 22 times starting from the leg up to his torso, up to his chest. Twenty-two times with no head shot. So he inflicted as much pain as he could and also did it in a fashion that to make sure that he knew Halloran would die.

FEYERICK: In a case of wrong place, wrong time, Michael Donahue was giving Halloran a ride home. Donahue was killed instantly, leaving behind a wife and three young kids, but to this day blame the FBI in the death.

UNIDENTIFIED MALE: John Connelly, he's a big reason why my father is dead.

PATRICIA DONAHUE, WIDOW: There's a hole in your heart when you're thinking about what's going to take place hopefully in the future, and then there's no future with that person so that's a pretty gut wrenching feeling.

FEYERICK: In 1994, Whitey Bulger's nearly 20-year reign came to an end in what was likely Connelly's parting gift, authorities say he alerted Bulger to a pending indictment and true to his word that he'd never return to prison, Bulger disappeared with his long-time mistress Kathleen Grieg leading to one of the FBI's greatest embarrassments and one of its largest manhunts.

(On camera): What was Whitey Bulger's life about?

SHEA: Power. Strength. Money. He was like a king, that guy. He was like a king.

FEYERICK (voice-over): Coming up, how one of America's most notorious gangsters remained comfortably hidden for nearly 16 years.

FUENTES: He became the Elvis of gangsters.

(COMMERCIAL BREAK)

FEYERICK (voice-over): Santa Monica is the place to retire. Beautiful beaches packed with people. An ideal place to blend in or disappear. That's precisely what Whitey Bulger did.

The reputed crime boss and his long-time girlfriend Catherine Greig setting up house blocks away from the ocean in a corner apartment partially hidden by trees. Bulger had planned ahead knowing he may one day run, says Tom Fuentes who spent years tracking the fugitives.

FUENTES: He had, you know, millions of dollars in cash. He took off to a number of different countries and cities and put cash in security safe deposit boxes that he could access later and so he didn't need to be contacting people. He could establish a new identity and eventually just take over a new name.

FEYERICK: That identity, Mr. And Mrs. Charlie and Carol Gasco, a self-described Chicago businessman and his younger wife who were into nutrition and long walks. And who secretly stuffed stacks of cash and heavy duty assault weapons in their apartment walls.

(On camera): These are your neighbors.

UNIDENTIFIED FEMALE: Yes, that's the way I saw them.

FEYERICK: And that's how you always saw them?

UNIDENTIFIED FEMALE: Always him with hat. I didn't know if he was bald.

FEYERICK (voice-over): Eighty-eight-year-old (INAUDIBLE) eventually befriended her upstairs neighbors. But there were privacy boundaries you did not cross. Like asking the Gascos to hold a spare key in case of emergency.

UNIDENTIFIED FEMALE: He says, well, let me talk to my husband. And then she came back and says, no, Charlie says that we -- he doesn't want you to give him anything. We don't want to.

FEYERICK (on camera): By all accounts Whitey Bulger kept a low profile. He didn't have any problems with the people who lived on his hall. According to one neighbor he didn't divulge much about himself but did say he'd originally come from Chicago and had fought in the Korean War.

That neighbor says a couple of times he caught Whitey Bulger on his balcony peering out with binoculars.

(Voice-over): From his crime days, Bulger knew the easiest way to get caught was to become complacent so he changed his patterns. Even when he came to getting his haircut, says this salon owner Fehima Betts.

FEHIMA BETTS, SALON OWNER: And I ask him to make appointment but he never did. He just walked in. And he never left me any number or anything.

FEYERICK: In fact, court documents showed Bulger and Greig had numerous fake identifies. After his arrest, Bulger told authorities he went gambling in Las Vegas, took trips to Tijuana to buy medication, and even returned to Boston on business, allegedly telling authorities he was armed to the teeth.

All the while the FBI was scrambling to find the gangster who had corrupted bureau agents.

BARRY MAWN, FORMER FBI SUPERVISOR: That's probably the worst thing.

FEYERICK: Former FBI special agent in charge Barry Mawn arrived in Boston two years after Bulger disappeared. He put Bulger on the FBI's top 10 most wanted list and had him featured on various crime shows, even in a "Dick Tracy" comic book.

MAWN: We weren't trying to hide him or not find him. And if you look at what we did it is impossible to draw that conclusion.

FEYERICK: Official say 12,000 leads came in over 16 years. Fuentes leading the FBI's international efforts says they followed up Bulger sightings in Ireland, London and South America.

FUENTES: There was thousands of police officers involved in that round-the-clock operation. So o any time there was a sighting of him, worldwide, everybody went full-bore to full up on those leads to try to find in. So in a way he became the Elvis of gangsters, he was constantly being spotted somewhere.

UNIDENTIFIED FEMALE: FEYERICK: The break in the case came in late June after the FBI paid for a public service announcement aimed at finding Bulger's girlfriend. It never even aired in Los Angeles. But a new story led to a crucial tip and an arrest three days later.

Bulger lured into the garage on a ruse that someone had broken into his locker. These are some of the 30 weapons FBI agents confiscated from Bulger's apartment.

UNIDENTIFIED FEMALE: Van number one. Van number two.

FEYERICK: After more than 5,000 days on the run, Bulger was brought back to Boston in handcuffs. Charged with 19 murders in court he denied them all. The damage he caused to the FBI still haunts the bureau to this day.

(On camera): In hindsight, do you think the FBI being acted too slowly to follow up on rumors that there was a leak and a dangerous leak that was letting Whitey Bulger run free?

FUENTES: Yes. I do think that.

FEYERICK (voice-over): How this plays out is anyone's guess. Bulger turns 82 in September. Will he cooperate? Stand trial? Cut a deal? Depends on who you ask.

SHEA: At that time --

FEYERICK: But his former drug boss John Shea, now a writer, says Bulger has the feds right where he wants them.

SHEA: He's playing them. Trust me. Psychologically he is playing them. Is he giving them information? Is he talking to them? You guarantee he is.

FEYERICK: So why here? Why so near the statue of Santa Monica? Consider this. In south Boston, Bulger grew up attending the church of St. Monica. Perhaps it's just a coincidence. Perhaps it's a clue. Some kind of locator. After all, Whitey Bulger left little to chance.

(BEGIN VIDEO CLIP)

ANNOUNCER: Next on CNN PRESENTS, Kaj Larsen explores why the U.S. Navy built this remote camp in the frigid arctic. And goes under the ice on a nuclear submarine.

And later --

UNIDENTIFIED FEMALE: No, it's not good. It is not good enough. ANNOUNCER: They don't just cheer on the sidelines.

UNIDENTIFIED FEMALE: That's it.

ANNOUNCER: A team determined to win a world championship at any cost.

UNIDENTIFIED FEMALE: Yes, this is it. This is what's going to determine the success of your year.

(END OF VIDEO CLIP)

(COMMERCIAL BREAK)

LARSEN (on camera): It's a pleasant 60 degrees at my home in L.A. today. But where I'm going it could be as cold as 60 below zero.

(Voice-over): Every two years the U.S. military conducts an operation in the Arctic Circle called Ice Exercise. Better known as ICEX. The Arctic region consists of eight countries that border a vast ice- covered ocean.

No one country owns the Arctic. There are some agreements governing who controls what territory, but as the ice melts, those lines in the map are changing and each nation is competing to extend its Arctic border to claim a greater piece of the valuable high north.

I don't really think that often about what's going on in the Arctic, but with global warming opening up vast riches of resources, and military exercises with nuclear subs converging underneath the Polar ice cap I wanted to know what's going on at the top of the ice world, and why.

As I launched to the Arctic, I talked via Skype with an Arctic expert, Professor Rob Huebert, about the spike in activity in the region.

PROFESSOR ROB HUEBERT, UNIVERSITY OF CALGARY: Most of the Arctic states are moving toward the improvement of their combat forces within that region and no one is of course calling for an Arctic war or conflict at this point in time. It is telling that we have two American attack submarines doing scientific research off the coast of Alaska.

LARSEN: Prudhoe Bay, Alaska, last stop in the U.S. before heading to ice station. It's time to get armed with some real cold weather gear.

(On camera): Bring on the Arctic.

UNIDENTIFIED MALE: Hopefully everybody has been given one of these books, "Survival in the Arctic."

LARSEN: The only way to get where we're going is a six-seater Bush plane. Finally, amidst a sea of Arctic ice, we spot the camp.

UNIDENTIFIED MALE: How you doing?

LARSEN (on camera): Hey, sir. How you doing? (Voice-over): With the U.S. submarines just below our feet I get my first look at a series of simple wooden huts built in the last two months to protect everyone from the extreme conditions.

(On camera): Look at this right here. Balmy 10 degrees right now.

UNIDENTIFIED MALE: Balmy, balmy 10 degrees.

LARSEN (voice-over): About 50 people from sailors to scientists have been adjusting to living at the ice station over the course of the exercise.

UNIDENTIFIED MALE: There's no magazine rack or anything in there? And also importantly is the effectiveness of toilet paper is significantly diminished at minus 40.

LARSEN: Just basic survival at the camp is a challenge.

(On camera): You can't go outside without carrying a rifle in case a Polar bear attacks. While we were standing on five feet of ice right now, we actually are moving 2 to 4 miles per hour. It's just floating.

Over the course of the one-month-long Ice Exercise it will move about 70 miles just from drift alone.

(Voice-over): So why am I here? Why has the Arctic become a hotspot?

(On camera): The world, it's physically clanging beneath my feat. With global warming the Polar ice cap is melting opening up an ocean for the first time since the ice age. This has created access to all kinds of new resources but it's also created competition at the top of the world.

(Voice-over): As the Arctic sea opens up, ships sailing from the Atlantic to the Pacific Oceans traditionally relying on the Panama Canal route can instead use the northwest passage saving thousands of miles and hundreds of millions of dollars.

A third of the world's natural gas is believed to be underneath the Polarized cap. The Arctic riches contain everything from oil to minerals to diamonds. But not everyone believes the quest for resources means competition. In Anchorage I was briefed by Professor Brigham Lawson.

PROFESSOR BRIGHAM LAWSON, UNIVERSITY OF ALASKA FAIRBANKS: There is complexity. Can be some friction. But not at a high level of military conflict issues that I would say.

LARSEN: Professor Lawson's colleague from the University of Calgary disagrees.

HUEBERT: I think at this point that we're on the cusp of being demilitarized. People are thinking much more military terms than they did since the end of the Cold War.

LARSEN: And back at ice camp, military exercises are indeed under way.

UNIDENTIFIED MALE: Maverick, roger, this is Atlas. All (INAUDIBLE) to Sierra, proceed.

LARSEN: The command hut monitors and communicates with the U.S. submarines 24 hours a day.

UNIDENTIFIED MALE: That's the New Hampshire here. And this is the Connecticut right here. And that's us in the middle.

LARSEN: In the past submarines had to surface to communicate. One of the systems in development allows the base camp to send texts to the submarine under the ice.

UNIDENTIFIED MALE: It is almost like a tweet, tweet submarines down here. I'll press in, there's a hydrophone down there that blasts out the sound. It sounds like crickets.

LARSEN: Many of the operations are classified. But what we saw an amalgam of testing, acoustics, submarine tracking, sonar, all under the umbrella of research.

(On camera): In your opinion what is the purpose of ICEX?

HUEBERT: Well, it's clearly -- there is a scientific basis and it's a nice little cover but the reality is I think that the American Navy is clearly showing that it is back.

LARSEN: This is a land grant. This is the U.S. presence in the high north. But we're not alone.

(Voice-over): Other nations are rapidly building their capabilities in the Arctic as well. Russia is creating an Arctic armed forces. Just this month announcing it will deploy two army brigades, including special forces. And it has resumed strategic bomber flights over the North Pole.

The Canadian government is building eight ice strength and patrol vessels. Denmark is deploying F-16s to Greenland. Norway is building five new frigates.

(On camera): In reality the battle is not for this desolate sheet of ice that I'm sitting on. The real value is beneath the surface.

(Voice-over): And that's where we're going next, on a nuclear submarine underneath the ice.

(COMMERCIAL BREAK)

DON LEMON, CNN ANCHOR: I'm Don Lemon live at the CNN world headquarters in Atlanta. Here are your headlines this hour.

The former head of Rupert Murdoch's British newspaper has reportedly been released on bail after her arrest earlier today. Police questioned Rebekah Brooks over the phone hacking and police bribery scandal at "The News of the World" paper where she was once editor. Also today London's police commissioner resigned over his connection to a former executive editor of the "News of the World" newspaper.

After being under police and public scrutiny for more than three years, Casey Anthony is now free but we don't know exactly where. Anthony walk out of an Orlando jail just after midnight. Twelve days ago a jury acquitted her of murdering her daughter. About 1,000 people were outside the jail in protest.

Security was high. Her attorneys say she has had multiple death threats.

The good news just keeps coming out of Los Angeles. Interstate 405 opened up at noon, 17 hours ahead of schedule. This after the dreaded carmageddon did not happen. That's what people were calling the expected gridlock after 10 miles of Interstate 405 were shut down for repair.

But drivers actually listened and the mayor is hoping for the same results when another shutdown is planned in 11 months.

Those are your headlines this hour. I'm don lemon. We now learn to "CNN PRESENTS."

LARSEN (voice-over): In 2007, a scientific exploration planted a Russian flag at the bottom of the Arctic seabed. What some publicly dismissed as a political stunt was privately considered in some circles a Sputnik-like moment.

According to secret leaked cables published by WikiLeaks, the rest of the world began scrambling to make sure they got a piece of the Arctic pie. That's how I came to be at a U.S. Navy facility in the Arctic circle to observe the escalating tension and activity in the region.

(On camera): Oh, yes, that's brisk.

(Voice-over): At daybreak we headed out to rendezvous with one of the two U.S. nuclear submarines patrolling in the Arctic.

(Voice-over): The helicopter dropped us and our equipment at the rendezvous site. A three-foot thick sheet of ice several miles away from the base camp. With no ocean in site hundreds of miles from the nearest cell phone tower it was hard to imagine how on earth a submarine would find me.

UNIDENTIFIED FEMALE: Are we a go for ice man surface? Over.

LARSEN: An X in the ice indicated where the submarine was to surface. Then the ground started to rumble. With 18 feet of the 353-foot long Seawolf-class sub on the surface, the ground crew takes chainsaws to cut their way through the ice to the hole. The then-commanding officer is first up from below.

LARSEN: After weeks under water the crew took a few precious moments of fresh air, then we loaded our gear and headed below deck. A small camera mounted on the top of the submarine was our only visual reference that we were making a descent 300 feet below the surface of the Polar ice cap.

(On camera): One of the amazing things about a modern submarine is that they're almost entirely self-sufficient. Like a biodome. They run on nuclear energy which means they can virtually go forever. They make their own oxygen with this oxygen generating plant right here.

They even make their own water through a process called hydrolysis where they scrub saltwater. So the only thing that actually limits a submarine is how much food they can carry.

COMMANDER MICHAEL VARNEY, USS CONNECTICUT SUBMARINE: The ship is in a six-hour rotation watch. And so what you end up doing is feeding the crew four times a day.

LARSEN: The submarine operates on an 18-hour day. A sailor essentially gets six hours on watch, six hours off, and six hours to sleep before it starts all over again. After our first meal on-board we began navigating the labyrinth passageways of the sub.

I ran into Petty Officer Joshua (INAUDIBLE) and asked about what life on the sub is like.

UNIDENTIFIED MALE: This is basically your, you know, home away from home. Opens up, we got bunch of treats, you know, different things that you need, all your clothes and magazines, or whatever you bring under way with you. You can bring any kind of snacks or whatever as long as it stays in your rack. You know you got to keep it in here, keep it clean.

LARSEN: Space is such a commodity that every nook and cranny is used for something. Finally, we descended to level three.

VARNEY: We're taking you now into the torpedo which is, quite frankly, the heart and soul of the submarine.

LARSEN: The USS Connecticut is an attack submarine designed to be quieter and faster than the Russian Akula class submarines. It carries an arsenal of up to 50 advanced capability torpedoes and Tomahawk land attack missiles. While it runs on nuclear power it doesn't carry nuclear weapons. Its purpose is to find subs that do reminding us of our primary reason for being here.

(On camera): Twenty-five years ago it was common for U.S. and Soviet subs to be playing cat and mouse underneath the ice. But with the break-up of the Soviet Union that activity ends. Now renewed interest in the Arctic has brought new players with rumors of Chinese subs operating in the region as well as the old guard U.S. and Russia. (Voice-over): As all the nations gear up, the USS Connecticut is preparing for war beneath the sea.

LARSEN: This was just a drill but the captain reminded the crew of the larger purpose.

VARNEY: It's always good to do this even up here while we conduct the exercises under the ice, because this is our main mission, taking this ship into harm's way and protecting our country. So great job getting on station. Boo-yah.

LARSEN: After traveling thousands of miles on planes, snowmobiles, helicopters, even submarines, we had come to a region influx. What seemed like a cold wasteland masked a rapidly changing environment. Vast resources are up for grabs in the Arctic.

Couched in the language of diplomacy, countries are preaching cooperation but simultaneously preparing for conflict.

The Cold War is over, but as I disembark the submarine, I was left with the feeling that there might be a new type of cold war under way at the top of the world.

(BEGIN VIDEO CLIP)

ANNOUNCER: Coming up, dedicated athletes. Willing to do whatever it takes to hold on to the world championship title.

GARDENER: You would expect a football player playing in the Super Bowl to play even if he had an injury.

(END OF VIDEO CLIP)

(COMMERCIAL BREAK)

SANDRA ENDO, CNN PRESENTS CORRESPONDENT (voice-over): Far from the sidelines of a football field, this defies the stereotype of what it means to be a cheerleader. It's called all-star cheerleading. It is as demanding and athletic as many sports. And in a decade it's become wildly popular. Fiercely competitive. And for some of the 200,000 young women involved, it's become their world.

Seventeen-year-old Mattie Gardener is one of the best all-star cheerleaders in the country. She's been competing since she was 7 years old.

GARDENER: Competitive cheerleading something really more action- packed and more difficult than high school cheerleading. To me, it is my passion. It became my sport. And now it's my life and it's what I do and it's pretty much who I am.

ENDO: Mattie trains year round at Cheer Extreme in Kernersville, North Carolina. One of the largest and most elite all-star cheerleading gyms.

GARDENER: It is a big commitment to be here, you know, every day for three to four hours. You know I'm doing homework in the car on the way here, I'm doing homework in practice breaks. I'm taking four AP classes so I really set high goals for myself and I think cheerleading has really taught me that, too, you know, don't settle for second- best.

ENDO (on camera): Do you feel like you've had to sacrifice any of your teenage years for this sport?

GARDENER: I wouldn't want to be anywhere else honestly. I mean this is what I love to do.

ENDO (voice-over): Her coach, Courtney Poe, says the dedication on Mattie's team is as intense as their practices.

COURTNEY POE, COACH: More than 50 percent of the team live two hours away. So that means getting home from school, getting in the car at 4:00, hoping they get no traffic, getting here for practice at 6:00, getting home almost at midnight, you know, and starting all over again.

GARDENER: I am in the center of the routine for the stunting part. You in a way carry the stunt sequence because the judges really focus in on the center of the routine.

ENDO: So what's the most challenging stunt you do?

GARDENER: It's called a ball-up 360 tick-tock. I think it is the most challenging right now on the market.

ENDO: But it's one you nail?

GARDENER: Yes, most of the time. Knock on wood. It was the first time anyone had ever done something like that, that skill last year at world's when I performed it.

ENDO (voice-over): Mattie is talking about the All-Star Cheerleading World Championship.

GARDENER: It's like a gymnast going to the Olympics. You know? That's their ultimate goal.

ENDO: Last year Mattie's stunt helped her team win a gold medal for the first time.

GARDENER: It was kind of just like all this emotion exploded and I was kind of threw my body on to the floor and it was really emotional. Just relief. Knowing that everything that I work for the past couple years had paid off.

ENDO: The team's success turned Mattie into a cheerlebrity. Now hundreds of fans want to be friends with her on Facebook.

GARDENER: I have 960 friend requests right now.

ENDO: With the 201 championship just weeks away, Mattie's team is counting on her to help them win gold again.

(On camera): You guys are going in as reigning world champions this year.

GARDENER: Yes.

ENDO: Pressure must be intense.

GARDENER: I definitely feel like it's harder to hold on to the top spot than it was climbing to the top last year. So it's definitely stressful.

ENDO (voice-over): Mattie feels the pressure perhaps more than anyone. She is still haunted by a devastating fall at the World Championship in 2009. The team's mistakes cost them the gold. Mattie blames herself.

GARDENER: You know, it's still in the back of my mind even though you try to push it out. I felt like I ruined it for everybody which is some hard feelings to go through.

ENDO: So Mattie pushes herself even harder. But just weeks before this year's competition, a sudden setback.

GARDENER: They told me that I had sprained my ACL and that other ligament. Hopefully I'll be able to practice for the rest of the time leading up to Worlds.

ENDO (voice-over): The World Championship of all-star cheerleading is just weeks away and Cheer Extreme's chances of holding on to the title suddenly seem to be slipping away. The team star, Mattie Gardener, is sitting on the sidelines with a painful knee injury.

GARDENER: It's really hot. It feels like fire honestly. When I first got hurt I said it felt like a hot knife and it kind of is a milder version of that. It was definitely bad timing. I fell out after stunt, almost tore my ACL which would have been really bad.

ENDO: After missing a week of training, Mattie cautiously takes the mat and works through the pain.

GARDENER: The more I do, the worse it gets. I mean I probably shouldn't be doing as much but it will be worth it in the end.

ENDO: Mattie is ready to do whatever it takes to hold on to their title. For the next three weeks, the team will spend four to five days a week in the gym, practicing for perfection. With their coach, Courtney Pope.

POPE: Who remembers the practice for four hours where I stood right here and we fixed every single person this way.

ENDO: Every step has to be in sync.

POPE: It is not together. This is no more synchronized in the opening than it was in January when we made it up.

ENDO: Ever flip, flawless.

POPE: No, it's not good and it's not good enough.

ENDO: They will do it over and over until they get it right.

POPE: Now hit one and stop. You're exhausted, right? But these are the moments. And World is won are not. Do the stunt again tired and mean it. Here we go.

(On camera): What are you going to do at World if your knee is acting up?

GARDENER: You would expect a football player to play in the Super Bowl to play even if he had an injury. And it's the same thing to me. I mean this is the only fix of our sport so obviously I'm going to get through it. We're not going to let anything stop us this year.

ENDO (voice-over): Saturday, April 30th, 2011. The first day of the World Championship. After an impressive performance, Mattie Gardener feels confident going into finals the next day.

GARDENER: Everything was perfect. Everything's hit, we were on time. It was synchronized. All the stunts were up. It was just unbelievable.

POPE: It's 271.1.

ENDO: But the mood suddenly changes when the team learns they're in third place.

POPE: Hey, hey, hey, hey. I know that we are disappointed in the ranking but the reality is that close -- do you want to go to third?

CHEERLEADERS: No.

POPE: Do you want to fix it?

CHEERLEADERS: Yes.

ENDO: Desperate to hold on to their title, they want to practice now. But it's near midnight and there are no open gyms.

POPE: One, two, three and four, five, six, seven, eight.

ENDO: So they wake up early for an emergency practice on the golf course behind their hotel.

POPE: You cannot like be a Jack Russell Terrier that decides you are going to get to your pyramid spot faster than anybody else does.

ENDO: Mattie is pushing through the pain in her knee.

GARDENER: You can't help but think, you know, this is it. This is what's going to determine the success of your year.

ENDO: No more time to practice. Now it's game time.

POPE: Let me your eyes. I watched your team 700 trillion times and I know we can be even better. Got it? I know we can.

You've got to talk about it and let's all just admit that like we're terrified. We're not like -- you can't practice to a point where we absolutely have this because who knows what's going to happen.

ENDO: Backstage the team tries to calm their nerves.

It begins near perfect. Then, Mattie's famous stunt comes crashing down. Watching the replay is tough. It wasn't the team's only mistake. And they know the gold medal is probably out of reach.

(On camera): Walk me through what happened here at World's today.

GARDENER: I mean I felt ready but I didn't feel like I knew I should. First part of the routine was just awesome. When it came to my specialty stunt, they kind of went bad that I don't really know what happened.

UNIDENTIFIED MALE: All right. We are moving on to the globes. The top three teams. The bronze champion, Cheer Extreme All-Stars.

ENDO (voice-over): After all the dedication, sweat and sacrifice, it's hard to hear they aren't world champions. Their rivals take home the gold.

GARDENER: It's hard not to feel like it was your fault. Pretty much going into this all we had to do was hit and we could win and that just -- it wasn't happening for us.

POPE: Mattie, she'll be fine. Mattie's a brilliant, genius and it takes setbacks and, you know, disappointments to really get to the best of who we all can be. And she's going to be something fantastic.

ENDO: It's an emotional end to a year of intense pressure and grueling training. But practice is starting all over for the next season. And Mattie will go for the gold again.

GARDENER: Maybe now that, you know, we're not on top we can come back next year and take it back but we'll just see what happens. I wouldn't consider not coming back for a second. It's -- it's just who I am. And, you know, I have to prove myself again now.

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UNIDENTIFIED FEMALE: He came to me and said mom, the (INAUDIBLE) school said I wasn't going. How? Because I'm going gay.

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